This animal resource improvement application requests funds to renovate and equip 2,332 ASF of existing vivarium and procedure space at the University of California, Irvine (UCI) to create the Rederivation &Internal Quarantine Suite (RIQS) to protect campus mouse populations from disease, thereby supporting PHS-funded researchers. The RIQS facility would provide a currently unavailable specialized space to isolate and rederive diseased or suspect animals to produce disease-free offspring via embryo transfer to clean foster mothers. RIQS features include: separate Quarantine (dirty) and Rederivation (clean) Suites;separation via airlock from other parts of the building, including separate entrance and exit doors to the "dirty" suite;filtration of both incoming and outgoing air;card coded locks on all doors;a pass-through for tissues;descending room pressurization from clean to dirty areas;carding procedures to prevent personnel from entering clean vivaria after entering the RIQS. RIQS will allow PHS-funded researchers to safely bring valuable strains of genetically engineered mice to UCI for rederivation, a practice stopped in 2006 due to disease. RIQS allows for the use of specialized practices (e.g. barrier maintenance) to protect valuable genetically engineered breeding stock, the quality of research data, and a significant campus and NCRR previous investment in animal facility space, especially for mice. A new ULAR policy will require all genetically engineered mice to be used for breeding be rederived into the new barrier space. This will sustain demand for the rederivation suite even after all current pathogen suspect mice on campus have been rederived. The RIQS offers an ideal location and environment to train staff in skills ranging from plugging and breeding strategies (animal technicians) to embryo transfers and other assisted reproductive technologies (senior and veterinary technicians).